Fertilizer



Patented 9, 1924.

. vmiw STATES ATE T OFFICE.

Armani) nu'rcnmson commas, or snwamm. NEW masnir, assmnon TO THE ELEC- rnro-smun'rmo AND ALUMINUM 00., or CLEVELAND, 01110, A oonrona'rronor OIIIO.

to contain hydrated silica, also artificial mixtures offertilizers, in' many instances,

' contain it in indefinite amounts as. an accidental impurity. Liebig, as early, as 1840, from his investigations of the composition of the ashes of various plants, thought silica necessary as a plant food. This resulted in experiments with potassium and sodium silicates to supply sillca augment the growth of grasses, cereals fandgplants containing very large percentages of silica 'in their skeletons. 'Knop and other plant physiologists, succeeded in growing; plants with salica supwards, ,:,.,when the Law of the minimum was proven and accepted, silica in any form was eliminated by agricultural chemists as an essential element to usein artificial min, eral fertilizers." (Soil conditions and'plant growth, by -E.';J.'Russell, 1915 Edition, pp. :30. 46, 112.) '-It is now universally assumed that'silica, clay, zeolites and feldspars in soils, furnish a superabundance of silica and therefore its addition as a fertilizer "is unnecessary. These substances and natural silicatesare so minutely soluble that the assumption is unx I abundance of the same is in such soils and furnishes normal amounts to success ve lgirowthsp Cultivation with exhaustion of umus and annual removal of crops, exhausts the soil faster than his replenished. Figuratively, the sponge has been removed that has accumulated'and retained'in sufficient amount this material which forms a posed to be absent as a nutriment,-and after Application flledDecember 2a, 1918. Serial n. 268,674.

large part of the natural Skeletons of plants. Cultivation also accelerates this lossthrough facilitating sub-soil drainage. Thus it is that soil water solutions in soilsfon cultivated lands largely free from humus, have become deficient in the" quantity of soluble silica that is needed 3 for maximum plant growth; therefore;

My invention consists in designingly using variable proportions of hydrated silica containing more than. fifteen (15) per cent. of water of hydration obtained from'calcium silicates containing molecular ratios ranging from 1 to 0.70: 1 calcium oxide to silica. to supply deficiencies of soluble silica required for plant growth. Such silica containing various amounts of water is securable by the action of carbonic and other acids and moisture upon various simple and complex silicates, artificial or natural.

It further-consists in the intentional addition or formation of designed proportions of such silicates inithe preparation of ferti lizer mixtures 01' substances, either by addition of such hydrated silica or such sili cates and an acid, with the intentional design of increasing or supplying intended amounts of hydrated silica to such mixtures. My invention'or discovery further embodies adding to soils, simple or complex calcium sili cates artificially prepared, characterized in that carbonic acid of the soil waters will decompose said compounds or mixtures with a liberation of hydrated silica of a more soluble type than those hydratedsilicas that commonly occur'in nature as minerals. The presence of the other essential fertilizers such as potash,ironoxide, phosphoric acid and soda as impurities in'said complex silicates,

is not to be avoided when there is a properv allowance of calcium oxide to silica in the mixture, so that upon the action of carbonic acid and moisture, there shall be formed a large amount of hydrated silica by their decomposition when used.

In my invention any silicate me be used in any manner so as to supply to .1: 1e soil or fertilizer mixtures, designed amountsof available added soluble silica. There, are certain silicatesand mixtures of silicates that can be artificially repared that will furnish a cheap source of soluble silica. To make my invention clear as to the use of hydrated silica from these specific materials,

I explain how to form them and the reason i for their use.

Many suggestions have been made involving the fusion of lime with native potash minerals such as occur in granites or potash schists and green-sand marls, with a view, to render available the potash therein for fertilizer purposes; Insuch attempts, it was. thought necessary to use potash minerals of high potash content and only suflicient lime to displace the molecular wei ht proportions of potassa that were in t e constltution of the potash silicates therein. It is now thought that such procesesare' valueless. In these attempts, I

' the product secured from, for instance,

. potash feldspar and lime, the'design 'was to lock the. lime in the form of an insoluble mono-calcium-aluminum silicate, freeing the potassa QLO) for solution. It was notrealized t at lmpure feldspars and other I potash 'mineral silicates mixed with free silica,- can be treated preferably at jfu'st silica in'the mixture, and at 'after' such 7 part of this fraction) one m'o their 'sintering temperature after mixing with two or up to two and one-half molecularweight proportions of lime toeach single molecular weight roportionl of alumina and ultimately two molecules of silica'together with water of chemical combination, the quantity of which inversely varies to a marked degree with temperatures to which soil waters are naturally subjected. These substances are the hydrated feldspars or zeolites of nature. They are permutites, and when immersed in a mixed solution, like soil waters, thy

' rcci rooally exchange, especially alk eart metal oxides and alkali metal oxides, inclusive of ammonia. These exchanges'are governed by the laws of mass action f as bearing upon the action of various ions, with variations of temperatures and variations of the density of different solutes. Zeolites are recognized as valuable soil constituents. v

Further, as a part of my invention, is the process of manufacturing the product described which consists in treating'in suitable furnaces, potash bearing silicioue rock s,

( lime present in all such as granites, schists, glauoonite mails and others or mixtures thereof, all contain-- ing large amounts of free silica, with two i or two and a fraction'molecular wei ht proportions of lime or limestone for eac single molecular weight proportion of silica in said mixture, and eating it to a temper ature not high'enoughto materially drive awa l the potash content and securing a pro not to be disintegrated or powdered, and (the and quantitative use of such as a fertilizer. In this process, iron oxide present in the mixture is beneficial bothbecause of its fertilizer value andbe cause by its use, ailo wer tem eraturesuflices for complete sintering or sion. 1

The reasons, though not vital,for this I cess of lime over the 2 to 1- ratio of limelto' vsilica are First to supply one molecular weight pr oportion of lime-to eachmolec ular welght proportion of alumina in the mixture, thus preventing a small amount of silica from .becominginsoluble throu h its formin with alumina, 'kaoli'nite I 0,- QSiO m O). Second,under conditions of imperfect mixing, an excess insures enough arts of [the charge 7 so that at least two m0 ecularv-weight proportionsof calcium oxidejcan combine with one molecular weight proportion of silica (SiO thus enabling 'all'the :potassa to assume 'a soluble form as'mono-potassiurn:

aluminate. Anexcessv of lime to silica over the 2% :1 ratio leads to higher melting point mixtures nd' possible volatilization of the potasSa. In the foregoin use in a. mixture ge igned to sinter, of two molecular; weight proportions off; lime or. calcium carbonate to each sin le molecular weight proportion of silica." n this case,

i I I have mentioned the .1

after treatment. with CO Usuch alumina'as ma be present'in themixture is leftffree as 'ydrated alumina and it naturally enters into combination with hydrated silica to form hv'drate'd' alumina silicates (A1 0,;

lll)

2 SiO,wH,O) or the insoluble clay substances of soils. "In doing this, however, Y

lime adheres naturally to the" com ound and some alkali :metal oxide, there ore, if a slight excess of lime over and above the two molecules of CaO to one of SiO, be em-. I

ployed in the mixture, and if the mixturebe well sintered the alkali metal oxides will'be freed during leaching with greater facility, and it may be supplied in excesseven to the extent of an added molecular wei ht proportion "of lime to each single molecu ar' I weight pro ortionof" alumina-inthe total mixture. he tri-calcium silicate istoorefractor for. ood economicalworkin he g Fform- (A's aring upon the chemistryo ending application, Serial No. 62,486, filed ilovember 20th, 1915.) r

'ing a proper mixture for sintering, see ,my/

- as impurities in My invention can also be carried out by employing sintered or fused mixtures of lime and silica or compounds of lime and silica preferablylower in their ratio of lime to silica than two and onehalf molecular weight proportions of lime to one of silica. In forming these mixtures of compounds, magnesium carbonate, iron oxide and potash the lime stone or silica are advantageous. Such mixtures can be formed in a rotary or other suitable furnace and by well known means, disintegrated to powders or mineral wool. So formed, it'always con-. tains a little alkali, iron oxide and alumina as impurities. Vhen calcium silicates are used, it" is desirable to have them as low in lime content and'high in silica content, as is consistent with the economical fusion. or

thus also performing a doution in the soil,

h of

ble function For maximum growt plans, deficiencies in all essential mineral fertilizers below that which is required for their full growths should be supplied to their soil waters in soluble form.

I. have made comparative plant growth experiments using chemically equivalent calcium oxide (CaO proportions incalcium silicate, calcium carbonate, calciumhydrate, calcium. carbonate plus hydrated silica mixed therewith, and calcium hydrate plus hydrated silica pletely and partially devoid of lime, and found that in those cases Where I was supplying hydrated silica to the soil, even as low as one quarter of a ton to the acre, such supply has'greatl'y augmented the growth and sintering and decomposition, when finely di- 'luxuriance' of nearly all the many plants teen per cent of water.

With two low an amount of vided', bythe action of carbonicacid and. moisture. Economical methods of producing them are well known. Tri-calcium sili cate 'sin-ter's at. too high a temperature and furnishes less hydarted silica, therefore, I would not recommend its use, though it will decompose by theaction of carbonic acid and moisture and furnish soluble silica to the soil. The mixture of lime and silica that melts at the lowest temperature, contains a little less than one molecular-weight proportion of calcium oxide to one of silica; .70 of molecule of lime to lof-s'ilica works well.

lime in the mixture, it ceases to be acted upon by carbonic acid .andmoisture, and the use of such should be avoided.

Hydrated calcium silicates, can be pro duced by treating infusorial earth, best when high in water of chemical combination, with slacked lime at ordinary temperatures. Infusorial earth may contain as high as thir- This reaction does not take place with ground crystalline silica, thus native hydrated silica may, by treatin with slacked lime and water, produceca cium silicates suitable for use.

If the described more soluble types of, hydrated silica, or the utilizable calcium silicates, be added to a soil devoid of any one of the other essential mineral fertilizer salts, no valuable results would be expected. 'In most soils these other essential salts occur in greater or smaller amounts. When calcium silicate is added, there isformed calcium bicarbonate in the waters of the'soil. It is known that calcium bicarbonate acting on hydrated silicates containing potassium oxide and alumina,-will liberate potassium oxide to form bicarbonate of potassium, and, therefore, the lime performs a double function of supplying lime to the soil waters and also soluble potassium salts. While the foregoing is known, one must conclude that the acid properties of silicic acid tend to release phos horic acid from its insoluble combinasubmitted to competitive tests. Thes'e experiments havebeen performed both in pots and on plots of land, and with each plant, repeated comparative experiments have been made, and in many cases repeated several times. The" aggregate result of thiswork has proven thatsilica in soluble form is needed to make upthat deficiency that exists in all soils that have been submitted to long cultivation. V

I find this also true when I supply lime, silica and potash secured by taking a-low grade potash feldspar, potash mica ormix- -tures of the like with silica, that has been sintered with lime to furnish the two plus molecular'weight proportions of lime to each single molecular weight proportion of siliea in the mixture. Experiments with such a sinter, I have carried on parallel with those that have been mentioned above, and the same show, in many cases, an improvement over using the proper proportioned amount of calcium silicate or lime plus silica. I, therefore, have discovered that in mixture, in soils both com l w grade potash containing rockscan, if I properly slntered or melted with lime (or limestone) be made to give up to the soil waters, hydrated silica with potassa K 0 and most of the lime employed, whilsta part of the lime will remain to form a calcium zeolite (or the like) with a relatively lower amount of contained silica than is in any of v two and a fraction'limeto one of silica, to

the action of carbonic acid and water.

Proper fineness of the materials I have mentioned when applied to the soil, can be easily appreciated by all those skilled in the art, and suchfineness of division was care fully observed in using the mixtures men- 80 mesh is favorable to good'results.

tionedin the competitive plant growth ex periments already described. A'fineness of I disclaim the use of solublealkali metal silicates for application to the soil or to add to fertilizer mixtures as a source of supply of soluble silica. Plant growth experiments, long ago abandoned, made with'them,,have led plantv physiologists into the error ofconsidering the soluble types of silica as non essential in the fertilization of plants. Thesecold experiments failed for a chemical reason thathas not beenjrecognized in this art, namely: all soils, fertilized or not, that are suitable for plant growth, must contain calcium bi-carbonate or, a salt of calcium. The action of soluble alkali silicates when solution and brought in contact with cal cium sa1ts, leads to the formation of insolu ble com pounds formed-of lime, alkali metal oxide and silica. When these old experiments were-made, as therewas: always em-.

ployed an excess of lime, or lime salt above that necessary to form this insoluble product, such insoluble salts formed. Therefore, when the experimenters thought they were furnishing :soluble 'silica. to the soil water, this silica was beingimmediately procipitated out and so rendered non-available to their plants. The deductions drawn from their experiments were, therefore, misleading. These deductions have found their way into the literature of this art. Looking up of the silica occurs even with-clay present, or with-zeolites in the soil, when soluble alkalisilicatesare used. The silica enters into combination to replace silica that has formerly beenleached away from zeolites during their slow process of degradation to clay. From these causes, the 01d comparative .plant growth experiments failed to showthe value of silica hydrates. This should have been recognized from the art relating to qthe manufacture of artificial stone from alkali silicates'or waterglass and said lime compounds, Also from the work performed'by'Daubree, T.. Sterry Hunt and others onyt-he reaction of alkali silicates in the artificial formation of insoluble minerals. I disclaim the use of natural monocalcium silicates, such as Wollastonite, and corresponding mono-magnesium silicates, suchas Enstatite, since they are too rare in nature to form the basis of any commercial process and have only been the subjectof scientific experiments.

In my application Serial No, 192,028, filed September 18, 1917, claims are made broadly to the feature of adding soluble calcium compounds described herein to fertilizer,

' and a fraction molecules of limefor each molecule of silica thereby forming a product largely decomposable by the action ofwater is-to be carried and carbonic acid and liberating hydrated silica containing more than [fifteen percent of water of hydration andadding the re-f sulting. product tov fertilizers deficient in solublesilica and limef v I I The'process of in creasing theamount of hydrated silica and lime thatimay exist in'the soil, which comprises addingfto a mixture of .fertilizer materials a sintered calcium silicate containing'two and a frac 7 tion molecules of lime. to;one of .silica and adapted to be decomposedbyjcarbonic acid and moisture into carbonate of, calcium and hydrated silica containing more than fifteen per cent ofwaterof hydration. v

- a fertilizer for supplying lime a d hydrated silica, the latter containing more 7 than fifteen per cent. of, water of hydration,

composed of a calcium silicate-combined with alkalimetal oxide and alumina, f the molecular ratio of lime to silicabeingtwo and a fraction to one. r

,4. A. fertilizer material composed of arti ficial calciumsilicate containing alkali and alumina, the molecular ratio of calcium oxide to silica being two and a fractiontojone.

.5. The process of fertilization.; which comprises subjecting the soil toa fertilizer com osed of artificial calcium silicate,fthe arti cial silicate containing the ratio of calcium oxide to silica varymg between' two and a fraction to! one and seven-tenths to One h I I.

6. The method of supplying to-deficient soils hydrated silica containing more than fifteen per cent of water of hydratiomwhich comprises subjectin I to carbonic acid and moisture calcium si icates containing variable percentages of alkalimetal oxide and alumma,,- said silicates having 'a molecular ratio of calcium-oxide to silica of two-and a fractionto one, and addingthe same to a fertilizer mixture,

a 7. A fertilizer composed of: artificially prepared calcium silicate having the molec: ularratio of twoand afraction molecules of calciumoxide .to onerof silica.

8. A fertilizen composed of artificially prepared calcium silicate of lower calcium value than the tri-calcium and containing impurities such as zeolite material and iron oxide. 7

- 9. The method of producing a fertilizer or fertilizer component, which comprises sintering silicious rocks containing potash, with lime in such proportions" as to form calcium silicate of higher value than dicalium and less than tri-calcium containing a quantity of'potassium alumina'te, the rewherein the ratio of calcium. oxid to silica.

varies between two and one-half to one and seven-tenthsat'o one.

12. A fertilizer material in pulve'rulent form comprising calcium silicate wherein the ratio of calcium oxide to silica varies betwee'n'two and one-half to one and seven.- tenths to one, and containing impurities such 'as commonly occur in limestone and silica.

13. Fertilizer materials in pulverulent form comprising artificial calcium silicate wherein the. ratlo of. calcium 'oxid to silica varies between twoand one-half to one and seven-tenths to one, and containing potassium metal oxides and alumina as im? purities.

14. The process of fertilization, which comprises sub ecting the soil to-a fertilizer composed of artificial calciumsilicate, other than dicalcium silicate, the artificial silicate containing the ratio of calcium oxide to silica varying between two and a fraction to one and se'ven-tenth'sto one.

15. A fertilizer composed of artificially prepared calcium silicate other than d1- calium silicate, of lower calcium content value than the tri-cal'cium and containing impurities such as zeolite' material and iron oxide.

. 16'. Fertilizer materials comprising artificial calcium silicateotherthan 'dicalcium silicate, wherein the-ratio of calcium oxide to silica varies between two and one-halfv toone and seven-tenths to one. i

17. Fertilizer materials in pulverulent form comprising artificial calcium silicate other than dicalciuln silicate, wherein the ratio of calcium oxide to. silica varies between twoand one-halfto one and seven tenths to one.- 7 7 -18. A fertilizer material in pulverulent form comprising calcium silicate other than dicalcium silicate, wherein the ratio of calcium oxide to silica varies between two and one-half tooneand seven-tenths to one, and containing im urities such as commonly occur in. limestone and silica.

-19. l ertilizer materials in pulverulent form comprising artificial calcium silicate other than dica cium silicate, wherein the ratio of calcium oxi'd to silica Varies between two and, one-half to one and seven-tenths to one, and containing potassium metal oxides and alumina as impurities.

Si ed at I Sewaren in the county of Mid esexand State of New Jersey this 16 day of December A. D. 1918,

ALFRED HUTCH'INSON GOWLES. Witnesses:

ALFRED W. Sonnmn,

Mmmr Kxonsnn. 

